Postoperative bone health following laparoscopic sleeve gastrectomy: a single-centre cross-sectional DEXA study

Bone mineral density (BMD) and calciotropic biochemistry after laparoscopic sleeve gastrectomy (LSG) have been inconsistently reported, and the long-term trajectory is poorly defined. We assessed postoperative bone mineral status (lumbar and femoral neck BMD with T- and Z-scores) and paired peri-operative calciotropic biochemistry after LSG. In this single-centre retrospective study, 61 adults underwent a single cross-sectional dual-energy X-ray absorptiometry (DEXA) scan a median of 29 months after LSG, with paired within-patient pre- and postoperative biochemistry. Bone status was classified by International Society for Clinical Densitometry (ISCD) criteria from menopausal status: osteoporosis (T ≤ − 2.5) in postmenopausal women and men ≥ 50 years, and low bone mass for age (Z ≤ − 2.0) in premenopausal women and younger men (osteopenia = T − 1.0 to − 2.5). Paired values were compared by Wilcoxon signed-rank tests with Benjamini–Hochberg false-discovery-rate (FDR) correction, and Spearman’s ρ related time since surgery to postoperative parameters. The median time since surgery was 29 months. Of 67 patients scanned, 6 postmenopausal women had osteoporosis on DEXA (indeterminate origin, no baseline scan) and were analysed separately, leaving 61. Mean BMI decreased from 45.9 to 29.4 kg/m²; 25(OH)D increased, parathyroid hormone (PTH) decreased, and calcium decreased slightly (all four p ≤ 0.008); all paired changes remained significant after FDR correction. Among the 12 patients in whom T-scores are diagnostic (postmenopausal women and men aged ≥ 50 years), 6 (50%) had femoral neck osteopenia; osteopenic-range femoral neck T-scores were present in 16 of 61 (26.2%) overall, descriptive in the premenopausal majority. No analysed patient met the osteoporosis threshold, and no premenopausal woman or younger man had bone mass below the expected range for age (Z ≤ − 2.0). Time since surgery correlated with postoperative BMI (ρ = 0.38) and β-CTx (ρ = −0.46), which survived FDR correction, whereas PTH correlations did not. At a single cross-sectional assessment a median of 29 months after LSG, no analysed patient had osteoporosis, although femoral neck T-scores clustered in the lower (osteopenic) range, descriptive in this predominantly premenopausal cohort. Because no baseline scan was available, these data cannot establish whether surgery altered bone mass, and support longitudinal surveillance with paired DEXA.